For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Credit Concentration (Details)	12 Months Ended
Credit Concentration (Details)	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Accounts Receivable [Member] \| Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage	34.30%	26.40%
Accounts Receivable [Member] \| Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage	22.10%	22.90%
Sales Revenue, Gross [Member] \| Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage	30.80%	29.30%	29.30%
Sales Revenue, Gross [Member] \| Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage	17.90%	17.20%	18.60%